1. Field of the Invention
The present invention relates to a radiotherapy device control apparatus and a radiation irradiation method, and more specifically to a radiotherapy device control apparatus and a radiation irradiation method for use in treating a patient by irradiating his or her affected area with radiation.
2. Description of the Related Art
Radiotherapy is known which treats a patient by irradiating his or her affected area (tumor) with radiation. It is desired that the radiotherapy provides a high therapeutic effect and that a dosage of radiation thereof irradiated to normal cells be smaller than a dosage of radiation irradiated to cells at the affected area.
The radiotherapy device is proposed which tracks a position of an affected area based on transmitted images photographed by applying diagnostic X-rays, and irradiates the position with a radiation for treatment. However, to achieve therapy with a high accuracy and reliability, it is desired that accuracy for detecting position of the moving affected area be improved.
Japanese Laid-Open Patent Application JP2001-291087A discloses an image aligning method (method and device for positioning image) capable of aligning two images flexibly depending on state of alignment or adaptively depending on characteristics of a subject. The image aligning method is a method of aligning two images of the same subject to be compared. According to the image aligning method, by setting at least a pair of interest regions and performing local matching between interest regions of each pair, positional relationship between the interest regions is automatically obtained. In addition, the alignment state between the interest regions is visually displayed and interest regions requiring realignment are selected. The selected interest region is manually aligned again as a subject.
Japanese Laid-Open Patent Application JP2001-325584A (corresponding to U.S. Pat. No. 7,035,445B) discloses an image aligning method capable of improving interpretation capacity by increasing comparison accuracy in comparing two or more images of the same subject to be compared and interpreted with each other. The image aligning method is a method of aligning two or more images. According to the image aligning method, a particular structure emphasized image obtained by emphasizing a particular structure in each of the two or more images is acquired and structural positional relationship between the acquired particular structure emphasized images is obtained. On the basis of the obtained structural positional relationship, the two or more images are aligned.
Japanese Laid-Open Patent Application JP2002-032735A (corresponding to U.S. Pat. No. 6,915,003B) discloses an image aligning method capable of achieving high accurate alignment by further suppressing misalignment of two images to be compared than conventional. The image aligning method is a method of aligning the two images of the same subject. According to the image aligning method, the two images are schematically aligned and local regions of high level of misalignment in the two images schematically aligned are selected. At least, on the selected local regions, realignment is carried out.
Japanese Laid-Open Patent Application JP2006-501922A (corresponding to WO/2004/034329) discloses a device of associating an image of the human body which should be stored with a current image with the high accuracy, desirably, in the order of millimeter or less. The image processing unit has an input for a signal of the current image of the human body volume receiving a motion with some motion phases, at least one input for a signal representing the motion phases of the human body volume included in the current image and a memory which stores previous images of the human body volume and the associated motion phases therein. The image processing unit associates the current image with the previous image having the motion phase closest to the motion phase of the current image.
Japanese Laid-Open Patent Application JP-H10-099456A (corresponding to U.S. Pat. No. 5,673,300B) discloses a method of correctly recording a treatment plan prepared for the patient in radiation treatment. The method is an operating method of a radiotherapy device for emitting at least one radiation beam having a controllable directional movement toward the patient. The method includes steps of (a) obtaining a plan tomography projecting set including a plurality of first radiography projections to the patient in predetermined treatment capacity of the patient located at a first position, (b) by activation according to a storage program using an electronic computer which receives the plan tomography projecting set, preparing a radiation treatment plan drawing at least one directional movement of the radiation beam with respect to the first position of the patient on the basis of a first plan tomography projecting set to provide desired treatment to the patient, (c) obtaining a check projecting set including a plurality of second radiography projections to the patient in predetermined treatment capacity of the patient located at a second position, (d) by activation according to the storage program using the electronic computer which receives the plan tomography projecting set and the check projecting set, comparing the plurality of second radiography projections with the corresponding projections of the first radiography projections and measured movement of the patient between the first position and the second position and (e) varying treatment for the patient according to the movement measured by using the electronic computer.